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View Full Version : Questions on replacing old Mallory caps on main board of Super Reverb

FuzzOff
12-28-2007, 04:16 PM
I have already completed the filter cap job (being very careful not to kill myself) and my next endeavor is replacing the old Mallory caps on the main board. Some of these caps have two positive leads, for a total of three leads. Are these hard to find? Is there a substitute? thx for any info.
slider313
12-28-2007, 04:22 PM
Use single 25/25's and twist the grounds together, solder the twisted lead and leave one for the ground connection.
BLC
12-28-2007, 04:38 PM
If these are the brown paper ones replace them, if they are the red and black dual + lead caps...these are poly and can be left.
Trout
12-28-2007, 04:52 PM
Some of these caps have two positive leads, for a total of three leads. Are these hard to find? Is there a substitute? thx for any info.

You can use 2 caps as mentioned above, or you can buy the dual section replacements FT Brand from Germany is a good replacement. Part number C-EM25-25-25 (http://www.tubesandmore.com/scripts/foxweb.dll/moreinfo@d:/dfs/elevclients/cemirror/ELEVATOR.FXP?item=C-EM25-25-25) at Antique electronics supply (http://www.tubesandmore.com/).

Trout
FuzzOff
12-28-2007, 04:59 PM
If these are the brown paper ones replace them, if they are the red and black dual + lead caps...these are poly and can be left.

Thanks for the info. I don't see any black dual positive leads in there, but lots of blue tootsie roll caps.
slider313
12-28-2007, 07:14 PM
The blue coupling and signal caps should only be replaced if they're leaking dc. Only replace the electrolytic caps with a positive+ and negative-, which should be brown paper dual 25@25v on early Super Reverbs.
Wakarusa
12-28-2007, 09:10 PM
Another bonus that comes from replacing the duals with singles is that you can replace the trem oscillator cathode bypass cap with a 50uF part (that'd be the one in parallel with a 2.7K resistor just North of V4 on the eyelet board). The higher capacitance makes the oscillator more reliable at lower frequencies.
FuzzOff
12-29-2007, 12:39 AM
Thanks for all the advice guys, got her working and replacing those caps did the trick. I also went ahead and did the three prong mod, I got sick of getting shocked everytime I touched something.

All the static is gone and she sounds as good as EVER. Converted to a head and running into a Weber Blue Dog Alnico. This is an incredible combination. I'm a happy camper.